The present invention relates to contour mapping systems and methods for mapping the contour of an object. The invention is particularly useful for mapping the curvature of the spine of a human being in order to detect spine deformities, such as scoliosis and kyphosis, and is therefore described below with respect to this application. The invention also relates to probes particularly useful in such a contour mapping system.
Scoliosis refers to a lateral spinal curve of a certain degree that affects an estimated 500,000 adults in the USA. The most common form of scoliosis, called idiopathic (i.e., of unknown origin), is so named because its real cause is unknown. There is a higher tendency for scoliosis to run in families, with many more affected girls than boys; thus adolescent girls over the age of nine are five times more likely to be diagnosed with scoliosis than boys of the same age. Early detection of scoliosis can lead to effective treatment. Currently, scoliosis is treated by special braces, surgery, or by a combination of both.
Screening for scoliosis detection has been adopted in most of the U.S. schools and in most of the Western World countries. Between 10 to 30% of the children that undergo a simple examination at school are advised to visit a pediatrician/orthopedist for a more thorough investigation and treatment recommendation. Approximately 30% of the latter are found to require long term treatment.
The basic tool for detecting scoliosis, and for quantifying its severity, is the spinal roentgenogram consisting of full length radiographs of the spine, one frontal and another sidewise. This is also the tool used by the physician during the long period of treatment and follow up.
Thus, a treated child will be exposed to a significant number of X-ray procedures, two to three double sessions per year. As a result, there is a concern about the cumulative effects of this high dose radiation. Recent publications reveal a three to four times higher risk to develop breast cancer and a number of thyroid cancers in women undergoing repetitive X-ray exposures as part of their scoliosis treatment. In spite of efforts to reduce the radiation dose, there is still a higher lifetime risk of cancer from spinal radiographs among people with adolescent idiopathic scoliosis.
Therefore, there is a real need for an alternative device, system and method capable of being used for the same diagnostic function as the X-ray today but avoiding the radiation exposure hazard, especially for young people, arising from multiple exposures during a long period of treatment. There is also a real need for a device, system and method capable of providing more detailed information about the examined spine, such as the degree of curvature of the spine, or the degree of rotation and/or deformation of any particular vertebra therein.
A number of alternative systems are described in the literature for measuring spine curvature in order to avoid the health hazard of radiation; see for example U.S. Pat. Nos. 2,324,672; 4,036,213; 4,600,012; 4,664,130; 4,760,851; 5,251,127; and 5,471,995. However, no system has yet proved to be entirely satisfactory. Efforts are therefore continually being made to develop systems, devices and methods for measuring the spinal curve in a manner which enables more precision, and which can be performed more conveniently, than the existing systems.
An object of the present invention is to provide a novel probe, contour mapping system and method for mapping the contour of an object, paticularly a person""s spine in a precise, convenient and simple manner.
Another object of the invention is to provide a novel probe, contour mapping system and method for measuring the curvature of the spine of a person in order to detect and/or treat for spine deformities, such as scoliosis or kyphosis.
According to one aspect of the present invention, there is provided a probe for use in a contour mapping system, the probe being constructed so as to be carried by a user""s hand with the tip of at least one finger of the user""s hand movable along the outer surface of the object whose contour is to be mapped; the probe including a position sensor to be located at a predetermined position with respect to the finger tip for sensing the position of the probe, and thereby of the finger tip, as the probe is moved by the user""s hand along the outer surface of the object whose contour is to be mapped.
The user""s finger or fingers are thus utilized as the xe2x80x9cfeeling partxe2x80x9d of the probe. This not only simplifies the construction of the probe, but also exploits the sense of touch for following the curvature to be mapped. Such a system is therefore particularly useful for mapping the curvature of a person""s spine, but it will be appreciated that it could be used in other applications involving the mapping of the contour of other objects.
One preferred embodiment of the invention is described wherein the probe is constructed for grasping by the user""s hand with the tip of at least one finger in a predetermined position with respect to the position sensor carried by the probe. The described probe includes a handle graspable by the user""s hand, and a finger supporting member fixed at one end of the handle for supporting the user""s index finger at the predetermined position with respect to the position sensor. In this embodiment, the position sensor is fixed within the finger supporting member.
A second embodiment is described wherein the probe is constructed for mounting on at least one finger of the user""s hand, with the position sensor at the predetermined position with respect to the finger tip. In the described embodiment, the probe is constructed for mounting on two adjacent fingers of the user""s hand with the finger tips exposed for direct contact with the object whose contour is to be mapped.
According to a further embodiment, the probe may also include an ultrasonic transducer for sensing the physical structure of the object whose contour is to be mapped.
According to another aspect of the present invention, there is provided a probe for contour mapping the outer surface of an object comprising: a position sensor carried by the probe for sensing the position of the probe as it is moved along the outer surface of the object whose contour is to be mapped; and an ultrasonic transducer carried by the probe for sensing the physical structure of the object whose contour is to be mapped.
According to further aspects of the invention, there is provided a contour mapping system for mapping the contour of an object, comprising a probe of any of the above embodiments, and a position tracking system for tracking the movements of the position sensor of the probe, and thereby of the finger tip of the user""s hand, as the probe is moved with the user""s hand along the outer surface of the object.
In the embodiments described below, the object whose contour is to be mapped is the spine of a person, and the system includes a data processor programmed to display data regarding the person""s spine as mapped by the probe. The data processor may also be programmed to compute and to display various characteristics of the mapped spine, such as the curvature of the spine, the distance between adjacent vertebrae, and/or the rotation or deformation of any particular vertebra in the spine.
According to yet another aspect of the invention, there is provided a method of examining a subject""s spine, comprising: providing the hand of an examiner with a probe having a position sensor at a predetermined location with respect to a finger tip of the examiner""s hand; moving the finger tip along the spinous processes of the vertebrae of the subject""s spine; upon feeling a spinous process with the finger tip, recording the position of the probe, and thereby of the felt spinous process; and utilizing the recorded positions of the felt spinous processes to calculate and display the curvature of the subject""s spine.
According to a still further aspect of the invention, there is provided a method of examining a subject""s spine, comprising: moving a position sensor along the outer surface of the subject""s spine to map the subject""s spine curvature; and utilizing an ultrasonic transducer to examine the physical structure of at least one vertebra of the subject""s spine to detect deformation and/or rotation of the examined vertebra.
According to further features in one preferred embodiment of the invention described below with respect to this aspect, the position sensor maps the subject""s spine curvature by sensing the spinous processes of the vertebrae in the subject""s spine, and the ultrasonic transducer examines the physical structure of at least one vertebra by sensing and displaying the location and contour of the two transverse processes relative to each other and to the spinous process of the examined vertebra such as to provide an indication of the rotation and/or deformation of the examined vertebra.
As will be described more particularly below, such a probe, system and method may be used for examining the spine of a subject and for providing detailed information about the examined spine without subjecting the subject to the hazards of radiation.
Further features and advantages of the invention will be apparent from the description below.